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[net-next] liquidio: fix format truncation warning reported by gcc 7.1.1

Message ID 20170926184827.GA3512@felix-thinkpad.cavium.com
State Changes Requested, archived
Delegated to: David Miller
Headers show
Series [net-next] liquidio: fix format truncation warning reported by gcc 7.1.1 | expand

Commit Message

Manlunas, Felix Sept. 26, 2017, 6:48 p.m. UTC 
From: Satanand Burla <satananda.burla@cavium.com>

gcc 7.1.1 with -Wformat-truncation reports these warnings:

drivers/net/ethernet/cavium/liquidio/lio_core.c: In function `octeon_setup_interrupt':
drivers/net/ethernet/cavium/liquidio/lio_core.c:1003:41: warning: `%u' directive output may be truncated writing between 1 and 10 bytes into a region of size between 0 and 13 [-Wformat-truncation=]
       INTRNAMSIZ, "LiquidIO%u-pf%u-rxtx-%u",
                                         ^~
drivers/net/ethernet/cavium/liquidio/lio_core.c:1003:19: note: directive argument in the range [0, 2147483647]
       INTRNAMSIZ, "LiquidIO%u-pf%u-rxtx-%u",
                   ^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/cavium/liquidio/lio_core.c:1002:5: note: `snprintf' output between 21 and 43 bytes into a destination of size 32
     snprintf(&queue_irq_names[IRQ_NAME_OFF(i)],
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       INTRNAMSIZ, "LiquidIO%u-pf%u-rxtx-%u",
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       oct->octeon_id, oct->pf_num, i);
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/cavium/liquidio/lio_core.c:1008:41: warning: `%u' directive output may be truncated writing between 1 and 10 bytes into a region of size between 0 and 13 [-Wformat-truncation=]
       INTRNAMSIZ, "LiquidIO%u-vf%u-rxtx-%u",
                                         ^~
drivers/net/ethernet/cavium/liquidio/lio_core.c:1008:19: note: directive argument in the range [0, 2147483647]
       INTRNAMSIZ, "LiquidIO%u-vf%u-rxtx-%u",
                   ^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/cavium/liquidio/lio_core.c:1007:5: note: `snprintf' output between 21 and 43 bytes into a destination of size 32
     snprintf(&queue_irq_names[IRQ_NAME_OFF(i)],
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       INTRNAMSIZ, "LiquidIO%u-vf%u-rxtx-%u",
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       oct->octeon_id, oct->vf_num, i);
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix them by changing the type of the "i" local variable from int to short.

Signed-off-by: Satanand Burla <satananda.burla@cavium.com>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
---
 drivers/net/ethernet/cavium/liquidio/lio_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

David Laight Sept. 27, 2017, 9:04 a.m. UTC | #1 
From: Felix Manlunas
> Sent: 26 September 2017 19:48
> gcc 7.1.1 with -Wformat-truncation reports these warnings:
> 
> drivers/net/ethernet/cavium/liquidio/lio_core.c: In function `octeon_setup_interrupt':
> drivers/net/ethernet/cavium/liquidio/lio_core.c:1003:41: warning: `%u' directive output may be
> truncated writing between 1 and 10 bytes into a region of size between 0 and 13 [-Wformat-truncation=]
>        INTRNAMSIZ, "LiquidIO%u-pf%u-rxtx-%u",
...
> Fix them by changing the type of the "i" local variable from int to short.

That probably adds pointless code bloat by forcing the compiler to
keep masking the value with 0xffff after every arithmetic operation.

About the only architecture that doesn't suffer the penalty is x86.

Until the compiler can correctly track the domain of values (and
be given hints about the domains) this warning is, IMHO, OTT.

	David
David Miller Sept. 30, 2017, 4:29 a.m. UTC | #2 
From: Felix Manlunas <felix.manlunas@cavium.com>
Date: Tue, 26 Sep 2017 11:48:27 -0700

> From: Satanand Burla <satananda.burla@cavium.com>
> 
> gcc 7.1.1 with -Wformat-truncation reports these warnings:
> 
> drivers/net/ethernet/cavium/liquidio/lio_core.c: In function `octeon_setup_interrupt':
> drivers/net/ethernet/cavium/liquidio/lio_core.c:1003:41: warning: `%u' directive output may be truncated writing between 1 and 10 bytes into a region of size between 0 and 13 [-Wformat-truncation=]
>        INTRNAMSIZ, "LiquidIO%u-pf%u-rxtx-%u",
>                                          ^~

Please just increase INTRNAMSIZ as needed.

Thanks.
diff mbox series

Patch

diff --git a/drivers/net/ethernet/cavium/liquidio/lio_core.c b/drivers/net/ethernet/cavium/liquidio/lio_core.c
index 23f6b60..55c5d44 100644
--- a/drivers/net/ethernet/cavium/liquidio/lio_core.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_core.c
@@ -899,11 +899,12 @@  int octeon_setup_interrupt(struct octeon_device *oct, u32 num_ioqs)
 {
 	struct msix_entry *msix_entries;
 	char *queue_irq_names = NULL;
-	int i, num_interrupts = 0;
+	int num_interrupts = 0;
 	int num_alloc_ioq_vectors;
 	char *aux_irq_name = NULL;
 	int num_ioq_vectors;
 	int irqret, err;
+	short i;
 
 	oct->num_msix_irqs = num_ioqs;
 	if (oct->msix_on) {